[Go-essp-tech] CMIP5_Amon pfull/phalf

[Sébastien Denvil]

Hi Denis,

we have the same error as you have, and I guess everyone with 
alternate_hybrid_sigma will follow the same track.

My understanding of what's going on and a possible workaround is (even 
tough not implemented yet) :

- The difference between time1 and time2 is that time2 is a 
climatological axis : cell_methods: time: mean within years time: mean 
over years
- But when you describe your vertical axis, the pressure level should 
have the same time axis as plev/phalf
- So your pressure level should be as well on a climatological axis and 
should be the result of a climatological mean.
- Not the same pressure level to describe  pfull/phalf and the other 
variables having an alternate_hybrid_sigma vertical.

Create another entry for ps (let's say ps2) but with climatological time 
axis :

     variable_entry:    ps2
     ...
     formula:          p(n,k,j,i) = ap(k) + b(k)*ps2(n,j,i)
     z_factors:        ap: ap b: b ps2: ps2
     z_bounds_factors: ap: ap_bnds b: b_bnds ps2: ps2
     dimensions:        longitude latitude time2


Generally speaking it could be clearer to have a CMIP5_Aclim as we have 
CMIP5_Oclim table for ocean climatological field.
FYI the cmor-list is the most appropriate one for this question.

Regards.
Sébastien

Le 16/11/2010 23:54, Denis Nadeau a écrit :
> Hi,
>
> I am trying to create phalf and pfull variable using
> "alternate_hybrid_sigma".
> I am having trouble due to the 2 time axis.
>
> 'time2' is needed by "pfull" and "phalf"
>
>      variable_entry:    phalf/pfull
>      ....
>      dimensions:        longitude latitude alevhalf/alevel time2
>
>
> 'time' is needed by "alternate_hybrid_sigma"
>
>      variable_entry:    ps
>      ...
>      formula:          p(n,k,j,i) = ap(k) + b(k)*ps(n,j,i)
>      z_factors:        ap: ap b: b ps: ps
>      z_bounds_factors: ap: ap_bnds b: b_bnds ps: ps
>      dimensions:        longitude latitude time
>
> I tried to create 2 time axis, one for 'ps' and one for 'phalf' or
> 'pfull' but I get an NetCDF error.
>
>
> Do you know how to create 'phalf/pfull'?
> What is the difference between axis 'time' and 'time2'
>
>
>
> Thanks,
> Denis
>
>
>
>    


-- 
Sébastien Denvil
IPSL, Pôle de modélisation du climat
UPMC, Case 101, 4 place Jussieu,
75252 Paris Cedex 5

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